Certain surgical procedures require both anterior and posterior access. For example, spinal procedures can require surgical access from both the patient's back and the chest. During the course of a surgical procedure, the patient undergoing surgery cannot be turned over between the supine position, (on his or her back), and the prone position (face down) in order to provide both anterior and posterior access to the surgeon without breaking the sterile field and redraping the patient. Surgical tables which provide both anterior and posterior access are therefore desirable.
Many surgical procedures, particularly minimally invasive procedures, also require positioning the patient on a surgical table and elevating the foot end of the table (called "trendelenberg") in order to gain surgical access to a desired region by shifting the patient's organs towards his or her head. Trendelenberg may also be used to increase blood flow to the patient's head to minimize the risk of shock. Other procedures require reverse trendelenberg, in which the head end of the surgical table is elevated in order to give the surgeon access to difficult to reach areas of the body.
Oftentimes, procedures which require both anterior and posterior access will also require trendelenberg or reverse trendelenberg. It is thus desirable to provide a table which will accommodate anterior and posterior access in both trendelenberg and reverse trendelenberg positions.
One type of surgical table is available which allows anterior and posterior access plus trendelenberg during a single procedure. The table includes a table top mounted to a single pedestal centered beneath the table. While this table is effective for giving surgical access in each of the desired patient positions, the pedestal limits the lateral rotation to approximately +/-20.degree..
The pedestal table also presents difficulties when image intensification is used during the surgical procedure. An image intensification unit is comprised of an x-ray transmitter and an x-ray receiver positioned at the top and bottom, respectively, of a large C-shaped member. To use an image intensifier, the C-shaped member is positioned around the body portion sought to be imaged. X-rays are directed at the body by the x-ray transmitter and are received by the x-ray receiver. Image intensification units are mounted on a base having wheels so that the units may be rolled up to the patient for imaging and then rolled out of the way to allow the procedure to proceed. Because the pedestals utilized in existing tables are configured to balance and support the patient's weight, they extend fairly broadly beneath the table top and thus prevent access to the patient's body by the C-shaped image intensification unit.
Thus, anterior-posterior procedures are oftentimes completed using two surgeries, one in which the patient is in a supine position and (following healing of the first surgical site) a second in which the patient is prone. Other times, two surgeries are used in which the patient is laterally positioned with the chest facing the surgeon to permit anterior access, and another in which the patient is laterally with the patient's back facing the surgeon to permit posterior access.
The two-surgery method increases patient risk because it involves two anesthetizations and twice the healing time of a single surgical procedure, and because the patient is twice exposed to risk of infection. Moreover, the hospital costs required for two procedures are far greater than for a single procedure.
Surgical tables utilizing a table top extending between a pair of vertical posts facilitate C-arm imaging, but it will be appreciated that a two post table is not easily configured for combined lateral rotation (to any angle) and trendelenberg positioning. It is therefore desirable to provide a surgical table which allows anterior and posterior access during a single procedure, which can be adjusted to the trendelenberg and reverse trendelenberg conditions, and which permits the use of C-arm imaging equipment.